ICC is Integrated Clock Controller, an important regulator for system clocks. There is no upgrade path from ME8 to ME9-10, only to the latest ME8 firmware, as provided at the (CS)ME thread. Since HP provides a full SPI image for your workstation, what you need to do is to make sure that you have the latest HP BIOS v3.92 applied.

Given that, I think I know what's going on now and if I'm right, it should affect all Z420 users. HP messed up while updating the ME firmware at the newer SPI/BIOS updates. Normally, to update it they need to do everything from scratch which takes a lot of time so what the community does (and probably OEMs as well) is to follow the Engine CleanUp Guide to clean and update the firmware at the same time. However, from experience we (the community) know that Flash Image Tool v8.1.40.1456 or earlier versions are bugged when it comes to Patsburg (C600) SPI images and the ME settings are not detected when following the CleanUp Guide (Step 5 > 2nd bullet). So I think that HP did the same procedure as depicted in that guide but was not aware that their (probably outdated) Flash Image Tool was bugged on the Z420's Patsburg platform and did not do the workaround.

Flash the attached (hopefully) fixed SPI image with the programmer, hold it with the clip (nice idea btw ), do "fptw -closemnf" and then "fptw -greset". Afterwards, check if ICC has valid OEM data.

Try a manual greset by removing all power (AC, RTC not needed) for 1 minute and press the power button 2-3 times while you wait.

Ah if you have kept such older BIOS then great. At the HP site I couldn't find anything old enough (same wrongfully upgraded ME firmware). Finding another dump won't help because we might not be able to clean it due to the FIT 8.1.40 bug with C600 SKUs. And yes, there is no point in trying to mess with ICC as it's very complicated.

We're not doing something wrong. I'm certain that the guide was followed by HP because of a harmless side-effect it has in which the Flash Image Tool version is set to be the same as the actual ME firmware (as seen in MEA) even though that may not actually be the case. For example, the firmware/tools/documentation packages from 8.1.40.1416 up until at least 8.1.65.1586 (last we've found) included Flash Image Tool 8.1.40.1456. However, BIOS 3.92 includes ME 8.1.60.1561 (in between 8.1.40 and 8.1.65 packages) but shows Flash Image Tool version of 8.1.60.1561 which makes no sense as it doesn't exist. If they had done everything manually (I don't blame them, only ME 8 C600 is bugged) the firmware would show as 8.1.60.1561 but FIT as 8.1.40.1456. Hopefully you get what I'm trying to say.





Anyway, it doesn't matter. We don't want very old BIOS because these had ME 7 which got later upgraded to ME 8. I think BIOS 2.55 with ME 8.1.10.1286 is a good candidate to flash as it is and test if the error goes away. FIT 8.1.10.1286 does exist. Don't forget to do a manual greset by removing all power (AC, RTC not needed) for 1 minute after re-flashing the SPI chip.

Well I don't think we can try something else, especially with the bugged FIT 8.1.40 in combination with the Patsburg platform. I suggest you flash the latest BIOS from HP and then proceed to close ME manufacturing mode to stop the error from showing. Then do a "-greset" and call it a day. I don't think you'll see any issue during everyday use.